There is no direct way to rename an overlay in AutoREALM. Instead, follow these steps:

1) Create a new overlay with the desired name by typing into the Active Overlay and pressing Enter.

2) Select the overlay you want to rename in the Overlay List and press Ctrl+Del to delete it.

3) Answer Yes to delete the overlay, and No to removing objects in that overlay.

4) Using the Replacement Overlay dialog, choose the new overlay name from the list and click Ok.